おかし(い)　in Japanese this word has long history originally interesting (old japanese story like Genji story ) next change as now english word Funny and also it means stornge /not normal change meaning even in Japan so Taste (funny) Sound( funny ) Feeling (funny ) I think poeple has each using by own judgements so you know language is could not keep in cage espcailly adjectives. in conversation may judge the word means correctly but standing alone make mean is own thing is one of the measure. "This Dictionary is funny" fit it in Japanese Language but not might fit in your idea of funny it is natural for me. It is hard to say how to explain how do you think " 私の子供のようすがおかしい”　the kid is bad condition or good condition . 95% or more Japanese poeple think child has bad condition. This is one chractoer of Language specifacation.

面白い is both that laugh-out-loud "funny" that you are looking for, and "hmm, interesting..." It functions as both meanings without losing the intensity of the first, like you were suggesting. It is totally about intonation, just like the word "funny" is in English. おかしい is similar to the later meaning of "funny," as in strange or interesting, but it kind of suggests that something is wrong. For example, コンピュータがおかしくなった would be something like "my computer's acting funny/strange." 変 is a more extreme "weird." Like "abnormal." So, the story that your friend tells you is 面白い, the way your computer is acting up is おかしい, and your little brother who likes to cosplay is 変.

Not all but many of E-J dictionaries published these days in Japan are made by the way telephone-game started from famous native dictionaries such as Oxford, Webster, and so on, so that the definitions are off the spot. Some old dictionaries compiled by Japanese leading authorities of English language may have much better definitions than other.